Stop Trump Coalition and One Day Without Us movement organised joint nationwide day of action.

Thousands of people protested outside Westminster on Monday (20 February) as MPs debated US President Donald Trump's state visit to Britain. The debate was in response to a petition signed by almost two million people calling for his invitation to be rescinded.

The rally in Parliament Square, which organisers claimed will attract more than 20,000 people, was to be addressed by speakers including joint Green Party leader Caroline Lucas.

Guardian journalist Owen Jones said of Trump: "He's a megalomaniac. He's a horrifying individual to have the title of most powerful man on earth.

"But I think people see him as a danger to the future of this planet, from climate change to war to racism."

The Stop Trump Coalition called a nationwide day of action, with many other protests co-ordinated by the One Day Without Us movement celebrating the contribution of immigrants to British society.

"We are calling for a nationwide day of action to stand up and say no to the future of hatred, racism and division that Donald Trump is trying to create – and to say no to the disgraceful complicity of Theresa May and the British government in supporting him," said the Stop Trump Coalition's website.

Calls for the state visit to be cancelled have been supported by London Mayor Sadiq Khan, who condemned the president's "cruel and shameful" policies.

Khan said Trump's travel ban aimed at people from seven Muslim-majority countries and the suspension of refugee admissions were reasons not to be "rolling out the red carpet".

During the parliamentary debate, SNP MP Alex Salmond complained that he couldn't hear ministers because of the demonstration outside.

"There are tens of thousands of people protesting outside. I'm having difficulty hearing the minister," he said. But he was reprimanded by the chair of the debate, Charles Walker, who said: "That is not eligible. Sit down!"

Labour MP Paul Flynn, who called the debate, said: "Outside, we have a Greek chorus of disapproval!"

Celebrities supporting the action include singer Paloma Faith, who said: "I'm backing the protests because I believe in human rights and compassion and Trump evidently does not."

In its official response to the petitions, the Government stated: "The President of the United States should be extended the full courtesy of a State Visit. We look forward to welcoming President Trump once dates and arrangements are finalised."

'We don't need empty symbols of love and unity, we need anger and action': Thousands of people at the anti-Trump protest in London tonight. pic.twitter.com/b56LS0Ynyr